import type { JSX, ValidComponent } from "@solidjs/web";
import { dynamic } from "@solidjs/web";
import { createMemo, omit } from "solid-js";
import { composeRefs, userRef } from "../../internals/compose-refs";
import { CompositeList } from "../../internals/composite/composite-list";
import { mergeRootProps } from "../../internals/merge-root-props";
import { resolveClassStyle } from "../../internals/resolve-class-style";
import type { BaseUIComponentProps } from "../../internals/types";
import { useComboboxRootContext } from "../root/combobox-root-context";

export interface ComboboxListState {
	empty: boolean;
}

export interface ComboboxListProps
	extends BaseUIComponentProps<"div", ComboboxListState> {
	as?: ValidComponent;
}

/**
 * A list container for the items. Renders a `<div>` element with
 * `role="listbox"` and wires `<CompositeList>` so items auto-register
 * their DOM order + labels for typeahead.
 */
export function ComboboxList(props: ComboboxListProps): JSX.Element {
	const root = useComboboxRootContext();

	const state = createMemo<ComboboxListState>(() => ({
		empty: root.flatFilteredItems().length === 0,
	}));

	const setListRef = (el: HTMLElement | null): void => {
		root.setListElement(el);
	};

	function onKeyDown(event: KeyboardEvent): void {
		if (root.disabled() || root.readOnly()) return;
		if (event.key === "Enter") {
			const ai = root.activeIndex();
			if (ai == null) return;
			event.preventDefault();
			const li = root.listRef.current[ai];
			if (li) li.click();
		}
	}

	const internal = {
		role: "listbox" as const,
		tabIndex: -1,
		get id() {
			return root.floatingRootContext.useState("floatingId") ?? undefined;
		},
		onKeyDown,
		onKeyDownCapture(): void {
			root.keyboardActiveRef.current = true;
		},
		onPointerMoveCapture(): void {
			root.keyboardActiveRef.current = false;
		},
		get "data-empty"() {
			return state().empty ? "" : undefined;
		},
	};

	const userClassStyle = resolveClassStyle(props, () => state());
	const userProps = omit(props, "as", "class", "style", "attrs");

	let merged: Record<string, unknown> = mergeRootProps(
		root.interactions.getFloatingProps(),
		internal,
	);
	merged = mergeRootProps(merged, userClassStyle);
	merged = mergeRootProps(merged, userProps);

	const Tag = dynamic(() => props.as ?? "div");
	const element = (): JSX.Element => (
		<Tag {...merged} ref={composeRefs(setListRef, userRef(props))} />
	);

	const hasItems = (): boolean => root.items() !== undefined;

	// In static-children mode the `dynamic()` element (and therefore the
	// `<Combobox.Item>` children it renders) MUST be created *inside* the
	// `<CompositeList>` provider so the items resolve the real
	// `CompositeListContext` and register their DOM order. If the element were
	// built in this component's own owner (e.g. `const element = <Tag/>`)
	// the item children would execute under ComboboxList's owner — outside the
	// provider — and silently fall back to the no-op context, so they would
	// never register, `index()` would stay `-1`, `listRef` would stay empty,
	// and keyboard navigation would be dead. Mirror `<Select.Positioner>`,
	// which inlines its `dynamic()` element inside `<CompositeList>` for the same
	// reason. (items-mode has no item-registration dependency, so the plain
	// element is fine there.)
	return (
		<>
			{hasItems() ? (
				element()
			) : (
				<CompositeList
					elementsRef={root.listRef.current}
					labelsRef={root.labelsRef.current}
				>
					{element()}
				</CompositeList>
			)}
		</>
	);
}